Nedbailo O. Thermophysical aspects of increasing the efficiency of the building with use of low-temperature heating systems and thermo-modernization of fencing structures

The dissertation is devoted to solving the problem of increasing the energy efficiency of buildings by introducing scientifically grounded newest technical solutions in fencing constructions of a building and combined low-temperature heat supply systems. On the basis of numerical calculations on the mathematical model of processes of non-stationary composite heat transfer taking into account the influence of year-round insolation on the shell of the building, thermal characteristics of the different-variant fencing structures were determined and the radiation energy component of their interaction with the environment was estimated. As a result of the calculations performed for the developed engineering methodology for determining the parameters of the thermal and thermal supply system of the thermal barrier fencing structures, for the first time, energy indicators of its operation with a heat pump in cold and warm periods of the year were estimated. Using numerical simulation with the consistent solution of heat transfer equations and corresponding boundary conditions in stationary mode, the values of the convective and radiation components of heat transfer through the typical translucent structures with single- and double-chamber windows are determined, as well as the value of their thermal resistance. In addition, the parameters of the heat transfer and aerodynamics of air in the typical room with the system of low-temperature water floor, as well as air heating in the quasi-stationary thermal regime based on the three-dimensional mathematical model in the Ansys 14.0 software package are calculated. A comparative analysis of exergic efficiency of operation of low-temperature and traditional systems of energy efficient houses with different heating devices is carried out. On the basis of the conducted complex researches, an engineering nomogram method for determining the heat engineering parameters of the water floor heating system, which is capable of providing the thermal regime of the premises in accordance with sanitary and hygienic requirements, has been developed. The scientific and technical provisions of building an energy efficient building with the use of a number of heat engineering solutions are grounded, among which is the use of soil heat exchangers with an air heat curtain of the facades of the building and a combined heat supply system based on the use of renewable energy sources (soil heat, insolation, etc.). As a result of the feasibility study of the implementation and operation of low-temperature systems with the use of a heat pump, in comparison with other heating systems to maintain the proper heating conditions of the premises, the main economic indicators of such technical solutions are estimated. The typical operating costs of typical buildings are calculated, depending on the source of heat supply, the heat engineering parameters of the fencing structures and the costs of primary energy.